This guide provides step-by-step instructions on how to use viewer markup tools or annotation tools. It covers various tools such as text highlighting, underlining, striking out, commenting, adding shapes, freehand drawing, inserting signatures, rubber stamps, images, callouts, and measuring tools. The guide emphasizes the importance of saving markups and provides tips for customization and accuracy. It is a comprehensive resource for anyone who wants to learn how to annotate and markup files effectively.